2021 BMW M135I: common problems and MOT failures
What MOT testers find on the BMW M135I first registered in 2021: we looked at the 6,959 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.
Common 2021 BMW M135I MOT failures and advisories
The share of 2021 BMW M135I MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.
- Tyres23% of testsRough price £70–£150
At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.
- Brakes7% of testsRough price £150–£350
At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.
- Wipers, windscreen and mirrors2% of testsRough price £15–£250
At the viewing: Check for chips in the driver's view, and test the wipers and washers.
- Lights and electrics1% of testsRough price £10–£80
At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.
- Suspension1% of testsRough price £120–£400
At the viewing: Listen for knocks over speed bumps, and look behind each front wheel for a snapped coil spring.
- Seats and seatbelts1% of testsRough price £80–£250
At the viewing: Pull each seatbelt sharply. It should lock, and retract cleanly.
Questions to ask the seller before buying a 2021 BMW M135I
Ask before you travel to see it. A seller who knows the car will have answers, and receipts.
- Can I see the service history and receipts for any big jobs?
Looking at a BMW M135I?
Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.
Other years
Every year of the BMW M135I compared
| Year | MOT tests | Most flagged |
|---|---|---|
| 2023 | 174 | Tyres 10% |
| 2022 | 2,491 | Tyres 24% |
| 2020 | 10,306 | Tyres 23% |
| 2019 | 2,763 | Tyres 24% |
Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of BMW M135I cars first registered in 2021. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score